CVE-2026-6347 – Mattermost

CVSS 7.6 IMPORTANT

“Collaboration platforms hold business conversations, files, and trust, so access weaknesses carry real impact.”

Mattermost released patches for four high-severity vulnerabilities affecting Mattermost. CVE-2026-4858 has a CVSS score of 8.0, which is High severity. CVE-2026-6346 has a CVSS score of 8.7, which is High severity. CVE-2026-5740 has a CVSS score of 7.5, which is High severity. CVE-2026-6347 has a CVSS score of 7.6, which is High severity.

The update addresses path traversal, information exposure, and uncontrolled memory allocation issues. One vulnerability could allow privilege escalation, while the others could expose sensitive data or affect service stability in affected Mattermost environments.

Key Details

Affected Product
Mattermost Mattermost Server
Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
CWE Classification
CWE-200
Patch this CVE on all your endpoints in under 5 minutes. First 200 endpoints are free forever, scale as needed.